Fix transport ship src and dst to always be water (#2832)

## Description:

Issue discovered by @DevelopingTom, posted on Discord. After merging
pathfinding PR, transport ships lost the ability to navigate between
land tiles. For now, the quick fix is to select adjacent water tile and
select it for pathing. Conquer logic still applies to original
destination on the shore.

## Please complete the following:

- [ ] I have added screenshots for all UI updates
- [ ] I process any text displayed to the user through translateText()
and I've added it to the en.json file
- [ ] I have added relevant tests to the test directory
- [x] I confirm I have thoroughly tested these changes and take full
responsibility for any bugs introduced

## Please put your Discord username so you can be contacted if a bug or
regression is found:

moleole

tests/Disconnected.test.ts

@@ -383,7 +383,7 @@ describe("Disconnected", () => {
       player1.conquer(game.map().ref(coastX, 4));
       player2.conquer(game.map().ref(coastX, 1));
 
-      const enemyShoreTile = game.map().ref(coastX, 8);
+      const enemyShoreTile = game.map().ref(coastX, 15);
 
       game.addExecution(
         new TransportShipExecution(